Update CCI Commands for - salesforce

[jenncarneiro]

Building off issue #101

update syntax in recipes in salesforce subfolder

This is not urgent, but it'll make our work more readable.
Until recently, you had to use cci task run generate_and_load_from_yaml with a bunch of arguments to get snowfakery to work. Now, you can use cci task run snowfakery with a slightly different set of arguments. I think we should move all of our recipes (and especially newer/bigger ones) to the new snowfakery task. There's a line of instructions in most recipes

This is the line that needs to change, most of the time:

# cci task run generate_and_load_from_yaml -o generator_yaml snowfakery_samples/npsp/Affiliations_Account_npsp.recipe.yml -o num_records 10 -o num_records_tablename Contact --org dev

which should read

# cci task run snowfakery --recipe snowfakery_samples/npsp/Affiliations_Account_npsp.recipe.yml with argument mapping that I haven't done yet

update main documentation (testing instructions)
run cci task info snowfakery to get the new arguments
find & replace in files